1. Technical Field
The invention relates to the field of valved devises and, more particularly, to a valved structure adapted for use as a breathing apparatus.
2. Background Art
Air masks used in conjunction with a breathing apparatus are well known in the art. Exemplary of such types of breathing apparatus include oxygen masks used for high altitude flying, emergency oxygen masks used for loss of pressure in aircraft, and medical oxygen therapy treatment units, both emergency and for hospital usage.
Oxygen masks are used with the breathing apparatus as an interface between the user and the source of gas or other desired fluid. The mask is fitted to the general contour of one's face about their mouth and nose, typically; Characteristic examples of such known oxygen masks used in oxygen therapy uses are those manufactured or sold by Hudson Oxygen-Therapy Sales Co. of Temecula, Calif., Life Support, Inc. of Melbourne, Fla., and Baxter Healthcare Corporation of Valencia, Calif.
As is generally the case with the above cited medical oxygen masks, such masks either do not include a valve regulating or controlling the passage of the gas or include a single valve that permits fluid flow in a single direction.
In U.S. Pat. No. 2,936,779 (Kindred) a mask having a flapper valve is disclosed. The flapper valve as taunt in Kindred permits the flow of the gas or other desired fluid in a single direction and forms a seal against the flow of the fluid in a reverse direction or when the flow ceases.
While the above cited references introduce and disclose a number of noteworthy advances and technological improvements within the art, none completely fulfills the specific objectives achieved by this invention.